IPA function is not configure for the CRPC unit cause ASON reroute failed

Publication Date: 2012-07-25Views: 65Downloads: 0

Issue Description

After the fiber is cut,ASON service cannot reroute.

T2000 version is V2R7C02Equipment is OSN6800NE version is V1R4C01B01p, 5.51.4.17The network is DWDM ASON network mesh and ring.The ASON service type is silver.

Alarm Information

After the fiber is cut. SC2 unit reports the R_LOS alarm and Amplifier unit reports MUT_LOS alarm but FIU unit does not report the MUT_LOS alarm.

Handling Process

This are the steps for handling process.1.After the fiber is cut, checking the alarm and power at SC2 and receiving Amplifier and FIU unitResult: SC2 unit reports the R_LOS alarm and Amplifier unit reports MUT_LOS alarm but FIU does not report the MUT_LOS alarm.2.Checking the receive power of FIU unit.Result: FIU unit can detect some power.3.Checking the CRPC unit status.Result: CRPC unit can detect some power and laser status is open.4.Checking the ASON service status.Result: ASON service cannot reroute.5.Shutdown the laser of CRPC unit.Result: FIU unit reports MUT_LOS alarm and ASON service reroute to other direction.6.Setting the IPA function for the CRPC unit and testing.Result: after the fiber is cut, CRPC unit automatic shutdown the laser. FIU unit and OAU unit report MUT_LOS alarm and SC2 reports R_LOS alarm and ASON service can reroute.

Root Cause

The root cause is that CRPC unit does not automatic shutdown the laser when the fiber cut which has some reflect noise power to FIU unit. Because FIU unit can detect some reflect noise power from CRPC, FIU unit will not generate the MUT_LOS alarm which cause the ASON service will not reroute.

Suggestions

IPA function must be configured when CRPC unit is used in order to automatic shutdown the laser and FIU unit can generates the MUT_LOS alarm for the ASON rerouting detection.Except for ASON fuction,IPA function must be configured for the safety when CRPC unit is used.